The goal of this project is to evaluate the chronic toxicity and carcinogenicity of two phthalate plasticizers, dibutyl phthalate (DBP) and di(2-ethylhexyl)phthalate (DEHP), following dietary exposures. 2-Year chronic toxicity and carcinogenicity studies of DBP and DEHP are in the in life phase. Both of these studies include perinatal exposures (exposure during gestation and lactation). Humans are likely to be similarly exposed to these compounds through the environment. Perinatal exposure occurs during critical periods of development and can result in differences in toxicity/carcinogenicity as compared to exposure starting only from adulthood. In the DBP study, rats were exposed perinatally prior to the start of 2-year study, while standard studies are being conducted in mice. DEHP includes two 2-year rat studies, one with perinatal exposure and one without, to evaluate the effect of perinatal exposure. Keywords: toxicity, carcinogenicity, diet, perinatal, phthalate, dibutyl phthalate, di(2-ethylhexyl)phthalate.